The invention relates to a method and arrangement for processing short messages in a mobile services switching centre of a cellular network.
The invention operates in a cellular network that contains a mobile services switching centre. The network comprises a home location register for permanent storing of location and subscriber data on radio telephones registered in the network. The geographical area covered by the network is divided into smaller mobile services switching centre areas (MSC area), each of which comprises a visitor location register for temporary storing of subscriber data on radio telephones visiting the MSC area and a mobile services switching centre interconnected with the visitor location register. Each MSC area is further divided into location areas, which are divided into cells. Each cell comprises at least one base transceiver station that is capable of establishing a radio link with the active radio telephones located in the cell.
In different cellular radio systems or radio telephone systems currently used or planned, the geographical area covered by the system is divided into separate smaller radio areas or cells in such a way that when a radio telephone or mobile phone is in the cell, it communicates with a fixed network via a base transceiver station located in the cell. The mobile phones of the system may freely roam from one cell to another within the system. One of these systems is the digital mobile phone system GSM (Global System for Mobiles).
In cellular radio networks, it is known to transmit short messages to a short message service centre that is separate from a cellular radio network. Recommendation GSM 03.40, ETSI/PT, February 1992 includes a description of such a system transmitting short messages. It describes interconnection of a short message service centre with a mobile services switching centre of a cellular radio network and operation of this short message service centre as it transmits short messages from outside the cellular radio network and from one subscriber (A-subscriber) of the cellular radio network to another subscriber (B-subscriber) of the network, or to a communicating means outside the network capable of receiving and/or transmitting short messages. Recommendation GSM 04.11, ETSI/PT 12, February 1992 provides a more detailed description of transmission of short messages on a radio path between GSM terminal equipment, a mobile services switching centre and a short message service centre.
The above described art solutions and their practical applications have focused on communication by means of short messages between the subscribers of a cellular radio system and the communicating means outside the system capable of receiving and/or transmitting short messages. Known solutions of this kind have thus granted that a separate short message service centre which requires space and financial resources, must be connected to the system, although the centre requires new arrangements separate from those required by a cellular radio network to control it and render it compatible with the network.